Toe-in gauge



March 1967 L. B. CASTIGLIA E AL 3,

' TOE-IN GAUGE Ofiginal Filed Feb. 16, 1961 5 Sheets-Sheet 1 IN V ENTORS LEO B. CASTIGLIA IIOHN CASTlGLlA BY THOMAS CASTIGLIA M, gimme, M1awwtwf h ATTORNEYS March 7-, 1967 L. B. CASTIGLIA ET AL TOE-IN GAUGE 3Sheets-Sheet 2 Original Filed Feb. 16, 1961 INVENTORS LEO B CASTiGLlAJOHN CASTIGLIA BY THOMAS CASTIGLIA ami aiflq w hw My? 2 ATTORNEYS March7, 1967 AsT|GL|A ETAL 3,307,263

' TOE-IN GAUGE Original Filed Feb. 16, '1961 3 Sheets-Sheet s INVENTORSLEO B. CASTIGLIA J'OHN CAST! GLIA BY THOMAS CASTIGLIA M,%@, W, 1m

ATTORNEYS United States Patent 3,307,263 TOE-IN GAUGE Leo B. Castigliaand John Castiglia, Plainview, and Thomas Castiglia, Hicksville, N.Y.,assignors to Wheel Aligning Necessities, Inc., a corporation of New YorkContinuation of application Ser. No. 89,843, Feb. 16, 1961. Thisapplication June 25, 1964, Ser. No. 379,440 15 Claims. (Cl. 33-46) Thisinvention relates to a wheel gauge and more particularly to a gaugewhich will measure and aid in the adjustment of the toe-in of thesteerable wheels of a wheeled vehicle having an undamaged frame byreference to a fixed reference plane. This application is a continuationof our copending application Serial No. 89,843 filed February 16, 1961.

Toe-in is the amount which the front wheels converge toward each otherat their front, or more accurately stated, toe-in is the amount eachwheel deviates from the straight ahead portion with ideal toe-in beingthat where the wheels converge towards the front in an exact equalamount from the longitudinal axis of the vehicle. Toe-in is a majorconsideration in steering wheel geometry as it effects tire wear and thesteering characteristics of a vehicle.

Heretofore toe-in has been measured by turntables, protractors, gaugesand the like. These devices have had the disadvantages of being eithertoo complicated for use by the average garageman or too cumbersome ortoo delicate for continued satisfactory use. Many of the devices do notmeasure toe-in with respect to the theoretical longitudinal axis of thevehicle. Others are dependent for their measurements upon referencepoints external to the vehicle. Generally, too, the present devicesrequire separate steps in checking the measurement and making thenecessary adjustment upon the vehicle thus unnecessarily lengthening theadjustment operation.

Our invention is of simple construction and rugged design and can beeasily operated by any person familiar with automobile mechanics. It isexceptionally accurate. The toe-in error is presented in a visualfashion such that the mechanic can see how much correction is necessaryfor each wheel while he is under the vehicle making the adjustments onthe tie rods by which toe-in is regulated.

Broadly, we propose a device comprising a pair of matched rigid members,one end of each rigid member having a securing means to secure to it thehub face of each front wheel or to the spindle, bearing, or any faceparallel to the true wheel plane. At the other end of each matched rigidmember is an optical unit in which is presented a split image of areference marker located upon the other rigid member. The hub face ofeach wheel is normally a machined surface and is an accurate referenceplane to which our invention is secured. It is a characteristic ofautomobiles that the end faces of the wheel hubs are normally machinedwhen the wheel is made in order to insure proper location of the spindleaxis. Further, the gauge may be attached to an adaptor which in turn ispositioned at right angles to and centered with respect to the spindleaxis. When the steering wheel of the automobile having an undamagedframe is centered and positioned for straight ahead driving and thesteering sector is on its high point, our novel gauge may be used tomeasure the angle of the wheels to which it is attached with referenceto the theoretical longitudinal axis of the automobile and thus a trueaxis from which to measure toe-in is offered independent of mechanicallinkages or reference points separate from the vehicle.

This gauge may also be used to measure the toe of the rear wheels of avehicle, as for example in vehicles having independent rear wheelsuspension. It may also be used to check the tracking of all fourwheels.

3,307,263 Patented Mar. 7, 1967 At the other end of each matched rigidmember is an optical unit in which is presented an image of a referencemarker located upon the other rigid member. Each optical unit broadlycomprises two vertically positioned mirrors, a split image mirror, and areference marker or target. By reason of the matched construction of therigid arm members, the optical units and reference markers are eachlocated the same distance from their respective hub centers when thedevices are attached to the steerable wheels.

When each rigid member is properly positioned, the mechanic workingunder the automobile sees from a distance and presented at the splitimage mirror of one optical unit a two-part image of the referencemarker of the opposite unit. Since the angle of the optical units ispre-set for the required degree of toe-in, it geometrically follows thatthe alignment of the split images can be effected only by adjusting thetoe-in of the wheels to the correct amount. It further follows that whenthe split images are aligned in both optical units that the'degree oftoe-in for both wheels is the same with respect to the spindle axis orthe longitudinal axis of the automobile where the automobile has anundamaged frame. It is understood that a similar split imagepresentation can be achieved by other optical means such as by lensesand prisms.

Referring to the drawings which more clearly illustrate our invention:

FIG. 1 is a bottom view of our invention in working position secured tothe machined end faces of the hubs of the steerable front wheels of avehicle;

FIG. 2 is a front elevation of one member of our invention as applied toa wheel partially shown;

FIG. 3 is a sectional view of one optical unit taken along line 33 ofFIG. 2;

FIG. 4 is a side elevation of the unit shown in FIG. 2;

FIG. 5 is an enlarged isometric view of the optical unit illustratingthe mirror arrangement;

FIG. 6 is a side elevation of another embodiment of of our inventionshowing its application to a wheel rim; and,

FIG. 7 is a sectional view taken along line 7-7 of FIG. 6.

Referring to the drawings in greater detail, FIG. 1 illustrates a rigidarm member denoted generally by 1 secured to the machined end face 2 ofthe wheel hub of the right steerable wheel of a wheeledvehicle, while 1'illustrates a similar member applied to the left steerable wheel. Itmust be remembered that FIG. 1 represents a bottom view looking up atthe front steerable wheels of a vehicle so that the left front wheelappears on the right side of the drawing. The member 1 is secured to thehub by means of a magnet 3 and centered upon the hub face by a centeringpin 4 which protrudes into the machined spindle center hole or drillpoint. Member 1 could also be secured by means of a clamp, bolt, cotterpin, or similar means. Centering could also be achieved by a cotter pinarrangement. Located at the other end of rigid member 1, which in thisembodiment is an L shaped or right angle casting, is a movable opticalunit 5 and a calibrated set screw 6. This movable optical unit 5 pivotson a vertical axis about point 7, the amount of deviation from normalbeing established by a control means comprising the set screw 6 and aspring 20 which urges the lug 21 attached to the optical unit intocontact with the set screw 6. The movable optical unit comprises mirrors8 and 9 and a split image mirror 10. Split image mirror 10 is locatedalong a line bisecting the angle between mirrors 8 and 9. A verticalreference marker 11 is allixed along this same bisecting line at point7.

A better understanding of the optical unit 5 is gained by reference toFIG. 5 where the mirrors 8 and 9, split image mirror 10 and refenencemarker 11 are more clearly shown. Split image mirror 10 has a clearupper half 12 and a mirrored lower half 13 or may Simply be a mirrorapproximately one half the height of mirrors 8 and 9.

Referring again to FIG. 1, arrows 14 and 15 represent rays originatingfrom reference marker 11 located upon member 1. Ray 14 is reflected bymirror 8' through the clear half 12 of split image mirror 10 to theobserver at point A. Thus the observer at A can see only the upper halfof reference marker 11 reflected in mirror 8. Ray 15 is reflected bymirror 9 upon the mirrored lower half 13' of split image mirror 10' andthence reflected to the observer at A. Thus the observer at A sees thelower part of reference marker 11 reflected upon the mirrored surface 13of split image mirror 10'. The two images so presented to the viewer atA meet only when the reference marker or target 11 of the optical unitis continued within a plane extending normal to the longitudinal axis ofthe vehicle and is parallel to the spindle axes of the wheels when thesteering wheel of the vehicle is centered. The overall effect is tocreate an optical square. The position of the optical unit 5 andtherefore the split image mirror is affected by two factors:

(a) the turning of the calibrated set screw 6 and (b) the movement ofrigid member 1 either in a vertical or horizontal plane.

If the calibrated set screw 6 is turned and pre-set to represent acertain amount of toe-in, and the optical units are in a horizontalplane established by levels 23 and 23', or other leveling means, itfollows that the only Way the split image can be aligned is by adjustingthe toe-in of the wheel, thereby moving the attached rigid member 1'. Itfollows that when set screws 6 and 6' are both set to the same degreeand the split images are aligned in both units 5 and 5, that the degreeof toe-in will be the same for both wheels. Since both rigid members 1and 1' are secured to hub faces 2 and 2', which hub faces are machinedsurfaces, adjustments by means of this invention will result in the samedegree of toe-in with reference to the longitudinal axis.

Using the gauge that we propose, any mechanic familiar with automobilescan adjust toe-in of a vehicle quickly, accurately, and conveniently.The process is simple. The vehicle is driven into the garage and leftstanding on the floor or put upon a conventional rack. The steeringwheel of the vehicle is then centered. A rigid member of our inventionis attached by means of the magnet to the machined end face of eachwheel and centered thereon by means of a centering pin which fits intothe machined spindle center hole. The optical units on each member arebrought into a horizontal plane by means of the level located upon eachmember. The adjustable support arm is then set to insure that the unitsare held stable with respect to the horizontal plane.

The mechanic then dials in the amount of desired toe-in by turning theset screw which positions the optical units. From a suitable position,usually beneath the vehicle, and while working on the tie-rods whichadjust toe-in, the mechanic can view the split image of one referencemarker in the opposite optical unit. By manipulating the tie-rod, whichadjusts toe-in, of the wheel on the same side as the optical unit atwhich he is looking, he can bring the split image in line. The operationis then repeated on the other side. When the split images of eachreference marker or target are aligned in each optical unit, the toe-inis correct for both Wheels.

This device is exceptionally accurate. Because of the relatively longdistance between optical units and because a split-image principle isused, a very slight deviation in alignment of the targets is multipliedand immediately noticeable. The device is convenient because it allowsthe mechanic to make his adjustments and his readings at the same timefrom beneath the vehicle where the adjusting means is located andwithout the need for a toe-bar or cumbersome linkages to hamper hismovements. It allows the job of adjusting toe-in to be done more quicklybecause it saves steps in adjustment and reading since both viewers maybe seen without undue change of position on the part of the mechanic.

Another embodiment of our invention is shown in FIGS. 6 and 7. Theprinciple of operation is the same as heretofore discussed. However, inthis embodiment the device is positioned upon the Wheel rim 30 by meansof rollers 31 and 32 and an adjustable support arm 33 all attached to arigid member 34. The optical unit 35, set screw 36, and level 37 aresimilar in all respects to the optical unit, set screw and level alreadydescribed.

In this particular embodiment, the separate matching members of ourgauge are placed upon the inner rims of the steerable wheels after thesteering wheel has been centered. The rollers act as a support on oneside of the matching member and allow the unit to be adjusted andleveled. The adjustable support arm acts to steady the gauge when inuse. Once the level position of the units has been set, the mechanicdials in the desired amount of toe-in by turning the calibrated setscrews. From a position beneath the vehicle, the mechanic can adjust thetie-rods and view the split images of the reference markers as presentedin the optical units. As the tie-rod is adjusted, the angle of toe-in ischanged, the optical unit and member positioned on that side are moved,and the split image presentation of the opposite reference marker isthereby changed. To bring the split images into alignment, the toe-in ofthe wheels must be the same amount as that represented by the pre-setposition of the set screws.

We claim:

1. A device for adjusting wheel toe-in of a vehicle comprising twoseparate matching members, a positioning means for positioning saidmatching members with respect to the wheel spindle and parallel to thewheel plane of said vehicle, an adjustable support arm secured to eachsaid matching member, a leveling means attached to each said matchingmember, and an optical alignment unit secured to each said matchingmember, each said optical alignment unit in turn comprising a referencemarker, a split image reflecting means for presenting a split image ofthe other said reference marker, and a control means for controlling theposition of each optical unit with respect to the longitudinal axis ofthe vehicle; whereby the correct toe-in of the said wheels is accomplished when the split image of each said reference marker in theopposite optical alignment unit is brought into alignment by adjustmentof said wheels.

2. A device for adjusting wheel toe-in of a vehicle comprising twoseparate matching members, a means for securing and centering saidmatching members to the wheels of said vehicle, and an optical alignmentunit secured to each said matching member, said optical alignment unitcomprising a movable mirror box, each said mirror box in turn comprisingtwo mirrors, a split-image mirror, and a reference marker, said movablemirror boxes, said mirrors, said split-image mirrors, and said referencemarkers being positioned such that an image of one said reference markerlocated upon one said matching member may be cast upon said split-imagemirror located within the other said miror box when said matchingmembers are secured to said wheels.

6. A device for measuring wheel toe-in of a vehicle having a steeringWheel and steerable wheels comprising two separate matching rigidmembers, a securing means for securing one end of each said rigid memberto a steerable wheel of said vehicle, a centering means for centeringeach said rigid member with respect to the steerable wheel to which itis attached, a movable optical alignment unit located at the other endof each said rigid member, a control means for controlling the positionof each said movable optical unit with respect to the longitudinal axisof the vehicle when the steering wheel is centered, and a referencemarker associated with each said movable optical unit to indicate theposition of the other said optical unit with said longitudinal axis.

4. A device according to claim 3 wherein the means for controlling theposition of each said movable optical unit is a calibrated set-screw forrotating said mirror about a vertical axis contained in the plane ofsaid spliti'mage mirror, the calibrations thereon representing varyingpositions of toe-in.

5. A device according to claim 3 wherein each said reference marker willbe in a plane normal to said longitudinal axis and parallel to thespindle axis of said steerable wheels when said steering wheel iscentered and when the toe-in of each said steerable wheel is equal.

"6. A device according to claim 3 having in addition an adjustablesupport arm on each said rigid member for regulating the height of saidarm and a level affixed to each said rigid member to insure that eachsaid optical unit is in the same horizontal plane.

7. A device for measuring wheel toe-in of a vehicle having a steeringwheel and two steerable front wheels comprising a right-hand right anglemember and a lefthand right angle member, a securing means located onone end of each said member for securing a leg of each said member tothe machined end face of the hub of each said front steerable wheel, amovable optical unit located on the other leg of each said member, eachsaid optical unit comprising in turn two mirrors at an angle to eachother bisected by a split-image mirror and a target, and control meansfor moving each said optical unit about a vertical axis; said targetassociated with one said optical unit presenting a split-image in themirror of the other said optical unit when it is not contained within areference plane extending normal to the longitudinal axis of saidvehicle and presenting a single image when it is within said referenceplane.

8. A device for adjusting wheel toe-in of a vehicle comprising twoseparate matching members, a means for positioning said matching membersupon the wheel rims of said vehicle, an adjustable support arm securedto each said matching member, a level attached to each said matchingmember and an optical alignment unit in turn comprising a movable mirrorbox, two mirrors, a splitimage mirror, a reference marker, and a controlmeans for controlling the position of each optical unit with respect tothe longitudinal axis of the vehicle.

9. A device for measuring wheel toe-in of a vehicle having a steeringwheel and steerable wheels comprising two separate matching rigidmembers, a securing means for securing one end of each said rigid memberto a steerable wheel of said vehicle, a centering means for centeringeach said rigid member with respect to the steerable wheel to which itis attached, a movable optical alignment unit having two mirrors and asplit-image mirror located at the other end of each said rigid member, acontrol means for controlling the position of each said movable opticalunit with respect to the longitudinal axis of the vehicle when thesteering wheel is centered, and a reference marker associated with eachsaid movable optical unit to indicated the position of the other saidoptical unit with said longitudinal axis; said two mirrors of saidoptical unit being positioned at such angle with respect to each otheras to both reflect light from a given source upon said split-imagemirror, and said split-image mirror being positioned longitudinallyalong a line bisecting the angle between the said two mirrors.

10. A device for measuring wheel toe-in of opposed wheels of a vehiclecomprising a right-hand right angle member and a left-hand right anglemember, a securing means located on one end of each said member forsecuring a leg of each said member to the machined end face of the hubof each said front steerable wheel, a movable optical unit located onthe other leg of each said member, each said optical unit comprising inturn two mirrors at an angle to each other bisected by a split-imagemirror and a target, and control means for moving each said optical unitabout a vertical axis; said target associated with one said optical unitpresenting a split image in the mirror of the other said optical unitwhen it is not contained within a reference plane extending normal tothe longitudinal axis of said vehicle and presenting a single image whenit is within said reference plane.

11. A device for measuring, comparing, and setting toe-in on opposedwheels of a vehicle with respect to a reference plane extending normalto the spindle axis about which said wheels rotate, comprising twoseparate rigid members, securing means for securing and centering oneend of each said member parallel to the plane of rotation of one of saidwheels, a movable optical splitimage viewer located at the opposite endof each said member, a control and indicator means for controlling andindicating the position of each said viewer with respect to saidreference plane, and a reference marker fixed to each said member aboutwhich each said viewer pivots; said securing means and the movableoptical viewer of one said rigid member being pre-calibrated withrespect to the securing means and viewer of the other said rigid memberto form an optical square such that when members are secured to opposedwheels, deviations of said wheels from said optical square appears assplit-reference marker images in said optical viewers whereby eachoptical viewer indicates the relation of the wheel to which it isattached to said optical square.

12. A device for measuring wheel toe-in of a pair of oppositely disposedwheels of a vehicle, comprising two rigid arm members wherein each saidarm member has a securing means mounted on one end thereof for securingone end of the arm to one of said wheels, centering means for centeringthe secured end of said arm with respect to the wheel center, adjustablesupport means on the free end of said armopposite said secured end forsupporting said free end, optical projection means including a tragetand an image receiving portion readible from beneath the vehical mountedon the free end of said arm and level means associated with the arm; thetarget'of one said optical projection means projecting into the imagereceiving portion of the other said optical projection means to give ameasurement of angular displacement of said arms with respect to eachother when said arms are in a common plane passing through the centersof both the steerable wheels as indicated by a common reading of thelevels asociated with both arms.

13. A device for measuring wheel toe-in of a pair of oppositely disposedwheels of a vehicle comprising two rigid arm members, each said armmember having one end adapted to be mounted on one of the wheels, meansfor centering the end of said arm member mounted on the wheel withrespect to the wheel, adjustable support means on the free end of saidarm member opposite from the mounted end for adjustable supporting thefree end vertically with respect to the center of the wheel, opticalline of sight means including a target and an image viewing portionmovably mounted on the free end of said arm member and viewable frombeneath the vehicle, and level means associated with the arm member forindicating when said arm members when mounted on both wheels are in acommon plane passing through the center of the wheels; both said opticalunits forming an optical square with respect to a line connecting thecenters of both wheels whereby toe-in of each said wheel may be measuredwith respect to said optical square.

14. A device for setting each wheel of a pair of 0ppositely disposedwheels of a vehicle to a predetermined amount of toe-in with respect toa line conecting the wheel centers; said device comprising a pair ofrigid members each adapted to be secured at one end to the center of awheel, level means associated with each rigid member, adjustable meansassociated with each rigid member for supporting the unsecured endthereof, an optical means on each said rigid member, each said opticalmeans having an image viewing portion and target producing portionwhereby the target producing portion of one said optical means mayproject a reference mark on the image viewing position of the other saidoptical means, and calibration means associated with each said opticalmeans whereby each said optical means may be preset with respect to theline connecting the wheel centers in order that an observer may observethrough the reference marks the angular position of the Wheels Withrespect to the line connecting their centers.

15. A device according to claim 12 wherein each said image receivingportion is adjustable with respect to the arm member 011 which it ismounted whereby each image receiving portion may be moved to a positionsuch that when the images of both targets of both optical means arealigned with the targets of both optical means, the Wheels on which thearms are secured are positioned at a preselected toe-in.

References Cited by the Examiner UNITED FOREIGN PATENTS Great Britain.Great Britain.

15 LEONARD FORMAN, Primary Examiner.

ISAAC LISANN, Examiner.

WILLIAM D. MARTIN, .TR., Assistant Examiner.

1. A DEVICE FOR ADJUSTING WHEEL TOE-IN OF A VEHICLE COMPRISING TWOSEPARATE MATCHING MEMBERS, A POSITIONING MEANS FOR POSITIONING SAIDMATCHING MEMBERS WITH RESPECT TO THE WHEEL SPINDLE AND PARALLEL TO THEWHEEL PLANE OF SAID VEHICLE, AN ADJUSTABLE SUPPORT ARM SECURED TO EACHSAID MATCHING MEMBER, A LEVELING MEANS ATTACHED TO EACH SAID MATCHINGMEMBER, AND AN OPTICAL ALIGNMENT UNIT SECURED TO EACH SAID MATCHINGMEMBER, EACH SAID OPTICAL ALIGNMENT UNIT IN TURN COMPRISING A REFERENCEMARKER, A SPLIT IMAGE REFLECTING MEANS FOR PRESENTING A SPLIT IMAGE OFTHE OTHER SAID REFERENCE MARKER, AND A CONTROL MEANS FOR CONTROLLING THEPOSITION OF EACH OPTICAL UNIT WITH RESPECT TO THE LONGITUDINAL AXIS OFTHE VEHICLE; WHEREBY THE CORRECT TOE-IN OF THE SAID WHEELS ISACCOMPLISHED WHEN THE SPLIT IMAGE OF EACH SAID REFERENCE MARKER IN THEOPPOSITE OPTICAL ALIGNMENT UNIT IS BROUGHT INTO ALIGNMENT BY ADJUSTMENTOF SAID WHEELS.